NCCER Millwright Practice Exam

The total distance the shaft travels from one peak to the other during one vibration cycle is known as what?

1. Amplitude

2. Displacement

3. Velocity

4. Frequency

The correct answer is: Displacement

The total distance the shaft travels from one peak to the other during one vibration cycle is referred to as displacement. In the context of vibration analysis, displacement measures how far the shaft moves from its rest position or equilibrium over the course of one complete cycle of motion. It encapsulates the movement's extent, and in waveforms, this distance is often represented from one extreme to the other (from a peak to a peak or from a trough to a trough). While amplitude sometimes also relates to the total distance of motion in a specific way, it is typically more precise in defining the distance from the centerline (or equilibrium position) to a peak or trough, which only describes half of the total displacement during a complete cycle. Velocity describes the speed and direction of the movement but does not quantify how far the shaft travels during a cycle. Frequency is concerned with how many cycles occur in a given timeframe, unrelated to the distance traveled during each cycle. Therefore, the proper term for the total distance covered in one complete vibration cycle is clearly defined as displacement.